As a result of their excellent tear strengths, tensile strengths, flex lives, abrasion resistances, and broad useful end-use temperature ranges, thermoplastic polyetherester elastomers are used in a wide range of applications. However, in certain applications it is desirable that thermoplastic polyetherester elastomer compositions be flame retardant. In some applications, halogenated, and in particular, brominated flame retardants can be used, but the use of such materials has drawbacks. For example, they may decompose or degrade at the processing temperatures used to prepare and mold the compositions, and the resulting degradation products can corrode the barrels of compounding extruders, surfaces of a molding machines, and other equipment. Furthermore, the degradation products can result in molded articles having poor surface appearance.
Thus it would be desirable to obtain a flame retardant thermoplastic elastomer composition that contains non-halogenated flame retardant. It would be particularly desirable to obtain such a composition that has good retention of physical properties after heat aging in air.
U.S. Pat. No. 7,074,857 and US patent application publication 2005/084694 describe melt-processable thermoplastic elastomeric compositions (also called thermoplastic vulcanizate compositions). U.S. Pat. No. 4,180,495 discloses the use of phosphinate salts to flame retard polyesters and polyamides. U.S. Pat. No. 6,255,371 discloses flame retardant comprising phosphinates, disphosphinates, or polymers thereof. U.S. Pat. Nos. 5,780,534 and 6,013,707 disclose flame retarded polyester compositions containing calcium or aluminum salts of phosphinic acid or diphosphinic acid. U.S. Pat. No. 6,270,560 discloses salt mixtures made from aluminum phosphinates, aluminum hydroxide and/or aluminum phosphonates and/or aluminum phosphates suitable as flame retardants for polymeric molding compositions.